JP2000032687A - Power distribution line control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power distribution line control system for transmitting a phase detection signal, where the voltage of a carrier signal is not superposed to a control device. SOLUTION: A biphasol phase detection signal output line for taking a phase detection signal out of a coupler that is connected to a power distribution line before and after a switcher which is attached to the power distribution line is connected to both ends of the primary coil winding of an insulation transformer, and at the same time, both ends of a secondary coil winding with a middle tap F are used as the phase detection signal output terminals of each of the above two phases, and the secondary coil winding middle tap F is connected to the ground, thus eliminating a carrier voltage component from the phase detection signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution line control system for monitoring a distribution line using a distribution line carrying signal and controlling a switch provided in the distribution line.

[0002]

2. Description of the Related Art In a distribution line control system, a plurality of switches are installed in a distribution line, and the switches on the substation side are opened and closed while monitoring the distribution line from a power supply side master station such as a substation. Is controlled. Here, as a method of signal transmission between a master station and a slave station, a carrier signal may be superimposed on a distribution line for transmission and reception between a master station such as a substation and a slave station on the switch side. In that case, the switch portion on the slave station side is configured as shown in FIG. In the figure, reference numeral 11 denotes a switch, a power supply-side coupler 14D is connected between a power supply-side distribution line 12D and a control device 13 in a distribution line 12 to which the switch 11 is connected, and a load-side distribution line 12F A load-side coupler 14F is connected to the control device 13.

FIG. 7 is a circuit diagram showing a specific configuration of a power supply side coupler 14D shown in FIG. 6. In FIG. 7, CC1 to CC3 are high voltage capacitors which also serve as coupling capacitors, and DC1 to DC3 are These are voltage dividing capacitors, both of which are connected in series to form a phase detection circuit. Phase detection signals for the U-phase and the W-phase are taken out from the connection point of the two capacitors and sent to the control device 13 (not shown). CF is a coupling filter, and a voltage dividing capacitor D
A transformer Tr4 inserted in series between the collective connection point at the other end of C1 to DC3 and the ground, a capacitor c and a coil L connected to the secondary side thereof, and between the transformer Tr4 and a control device 13 (not shown). Input / output of the carrier signal is performed. In addition, C1 to C3
Indicates the distribution line path-to-ground capacitance.

In FIG. 7, when attention is paid only to the U phase and the W phase, each of them can be represented by an equivalent circuit shown in FIGS. The distribution line ground capacitances C1 to C3 are equal to the high voltage capacitors CC1 to CC3 and the voltage dividing capacitors DC1 to DC3.
3, the capacity of the voltage dividing capacitors DC1 to DC3 is also larger than the capacity of the high voltage capacitors CC1 to CC3 on the slave station side.
Distribution line ground capacitance C1 to C3 and high voltage capacitor CC
Carrier voltage sharing in the capacity of 1 to CC3 can be ignored. Further, since the phase determination is performed based on the shared potential difference between the U phase and the W phase,
On the basis of the phase, the phase detection circuit can be represented as a simple circuit in which the carrier voltage is applied only to the U phase as shown in FIG.

[0005]

However, by adopting such a circuit configuration, the carrier signal is superimposed as a high-frequency signal synchronized with the commercial frequency power supply, and the peak value is 5.
It becomes an AC signal that reaches 00V. As a result, the phase detection signal while the carrier signal is being transmitted / received is transmitted in a state where the voltage of the carrier signal is superimposed on the ground potential. While it is possible, the control device that receives the phase detection signal is subjected to electrical stress. Therefore, the present invention
An object of the present invention is to provide a distribution line control system that transmits a phase detection signal to which a voltage of a carrier signal is not superimposed to a control device.

[0006]

SUMMARY OF THE INVENTION According to the first aspect of the present invention, a distribution line is monitored using a distribution line carrier signal and a switch is opened and closed by connecting a coupler before and after a switch attached to the distribution line. A distribution line control system for controlling, in which a high voltage capacitor and a voltage dividing capacitor are connected in series to a branch line extracted for each phase of the distribution line, and the other end of the voltage dividing capacitor is connected collectively to further connect a coupling filter. In the distribution line control system that connects and forms a coupler, extracts a phase detection signal from an intermediate connection point between the high-voltage capacitor and the voltage-dividing capacitor, and inputs and outputs a carrier signal through the coupling filter, the coupling is detected from the coupler. Two-phase detection signal output lines for extracting phase signals are respectively connected to both ends of the primary winding, and both ends of a secondary winding having an intermediate tap are connected to the two-phase detection signal output lines. Characterized by comprising a terminal Toshikatsu secondary winding isolation transformer with center tap and ground.

According to a second aspect of the present invention, a distribution line control for monitoring a distribution line using a distribution line carrier signal and controlling the switching of the switch by connecting a coupler before and after a switch attached to the distribution line. In the system, a high voltage capacitor and a voltage dividing capacitor are connected in series to a branch line taken out for each phase of a distribution line, and the other ends of the voltage dividing capacitors are collectively connected, and a coupling filter is connected in series and grounded. In a distribution line control system for extracting a phase detection signal from an intermediate connection point between the high-voltage capacitor and the voltage dividing capacitor and inputting / outputting a carrier signal through the coupling filter, a voltage dividing capacitor of the coupler is provided. Of the secondary winding is connected to the ground, one of the ground sides of the secondary winding is connected to the ground, and the other is a phase detection signal output terminal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of the first embodiment of the present invention, in which a portion mainly related to a phase detection circuit of a coupler section is extracted and shown. This circuit is provided on both sides of the power supply side and the load side with respect to a switch (not shown) provided with a distribution line, and a phase detection signal is transmitted to a control device (not shown). 6 to 10 for each part in the figure.
The same parts as those of the conventional example shown in FIG.

In this circuit, a primary winding of an insulating transformer Tr1 is connected to connection points A and B of U-phase and W-phase high-voltage capacitors CC1 and CC3 and voltage-dividing capacitors DC1 and DC3, respectively. Transmits a carrier signal via an output voltage corresponding to the potential difference between the U-phase and the W-phase. Also, the insulation transformer T
An intermediate tap F is provided in the secondary winding of r1 to be grounded.
The insulating transformer Tr1 does not need to transform the primary side and the secondary side of the series connection points A and B, and is used to insulate the primary side and the secondary side and eliminate the electrostatic coupling. .

FIG. 2 shows the circuit of FIG. 1 with the addition of the earth capacitance of the distribution line, and C1 in FIG.
ＣC3 is the ground capacitance. In FIG. 2, when a carrier signal is transmitted and received between a master station and a slave station, the U-phase and the W-phase can be respectively represented by the equivalent circuits in FIG. 3, and most of the carrier voltage is only transmitted by the high-voltage capacitors CC1 and CC3. Since they are shared, they can be represented in a simplified circuit as shown in FIG. Thus,
The potential of both series connection points A and B rises by the carrier voltage with respect to the ground potential.
And an intermediate tap F of the secondary winding of the insulating transformer Tr1 is grounded.

As a result, the absolute value of the shared potential difference between the U-phase detection signal and the W-phase detection signal does not change, and the
1 to a control device (not shown). That is, the control device can obtain the phase detection signal without being affected by the carrier signal even during transmission and reception of the carrier signal. Further, since the secondary winding intermediate part of the transformer Tr1 is grounded, even if the voltage on the primary side of the transformer Tr1 rises abnormally, it is possible to prevent the voltage rise on the output side.

FIG. 5 is a circuit diagram showing a configuration of an embodiment of the second aspect of the present invention, in which a portion related to a phase detection circuit of a coupler section is mainly shown. This circuit is provided on the power distribution line on both the power supply side and the load side with respect to the switch, and a phase detection signal is transmitted to a control device (not shown). In the drawings, the same components as those of the conventional example shown in FIGS. 6 to 10 are denoted by the same reference numerals, and description thereof will be omitted. In this circuit, the primary windings of the isolation transformers Tr2 and Tr3 are connected to both ends of the voltage dividing capacitors DC1 and DC3 connected to the U and W phases, respectively, and one ends of the secondary windings are collectively grounded. A phase detection signal corresponding to the potential difference between the U phase and the W phase is output between the other ends of the secondary windings.

In this circuit, similarly to the phase detection circuit of FIG. 1, when a carrier signal is transmitted and received between the master station and the slave station, both the U-phase and W-phase voltage dividing capacitors DC1 and DC3 are connected to the ground potential. However, since one end of the secondary winding of each of the insulating transformers Tr2 and Tr3 is collectively grounded, it is equivalent to the grounding of the secondary winding middle part. -The absolute value of the shared potential difference between the W phases does not change,
From the transformer secondary winding to the control device (not shown),
Sent without being affected by the carrier signal. Note that the capacity of the insulating transformers Tr2 and Tr3 may be extremely small.

[0014]

As described above, according to the first aspect of the present invention, the difference voltage between the two phase detection signals is taken out through the insulating transformer, so that the carrier signal and the phase detection signal are extracted. Signals are not superimposed, and phase detection during transmission / reception of carrier signals becomes possible. Further, since the carrier noise is no longer generated, the input of the electric stress to the control device is eliminated. Furthermore, since the intermediate tap of the secondary winding of the insulating transformer is grounded, the output voltage of the phase detection signal is prevented from abnormally increasing.

According to the second aspect of the present invention, both ends of the voltage dividing capacitor of the coupler are connected to the primary winding of the insulating transformer, one of the grounding sides of the secondary winding is grounded, and the other is phase-detected. By using the signal output terminal, the carrier signal and the phase detection signal are not superimposed, and phase detection during transmission / reception of the carrier signal becomes possible. Further, since the carrier noise is no longer generated, the input of the electric stress to the control device is eliminated.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing the circuit of FIG. 1 with the addition of a ground capacitance of a distribution line.

FIG. 3 is an equivalent circuit diagram of the U phase and the W phase of FIG.

FIG. 4 is an equivalent circuit diagram of the U phase and the W phase of FIG.

FIG. 5 is a circuit diagram showing a configuration according to an embodiment of the present invention;

FIG. 6 is a block diagram showing a configuration of a conventional example.

FIG. 7 is a circuit diagram showing a configuration of a conventional example.

FIG. 8 is a circuit diagram showing a configuration of a conventional example.

FIG. 9 is a circuit diagram showing a configuration of a conventional example.

FIG. 10 is a circuit diagram showing a configuration of a conventional example.

[Explanation of symbols]

 A, B Series connection point CC1 to CC3 Coupling capacitor CF Coupling filter C1 to C3 Capacitance to ground DC1 to DC3 Voltage dividing capacitor F Intermediate tap Tr1 to Tr3 Insulation transformer 11 Switch

Claims (2)

[Claims] 1. A distribution line control system for monitoring a distribution line using a distribution line carrier signal and controlling the opening and closing of the switch by connecting a coupler before and after a switch attached to the distribution line, A high voltage capacitor and a voltage dividing capacitor are connected in series to the branch line taken out for each phase of the distribution line, and the other end of the voltage dividing capacitor is connected together and a coupling filter is further connected in series to constitute a coupler. In a distribution line control system for extracting a phase detection signal from an intermediate connection point between a capacitor and a voltage dividing capacitor and inputting / outputting a carrier signal via the coupling filter, a two-phase detection signal output for extracting a phase detection signal from a coupler Wires are connected to both ends of the primary winding, and both ends of the secondary winding having an intermediate tap are used as phase detection signal output terminals of the two phases, respectively. Distribution line control system comprising the grounded connection isolation transformer. 2. A distribution line control system for monitoring a distribution line using a distribution line carrier signal and controlling the switching of the switch by connecting a coupler before and after a switch attached to the distribution line, A high voltage capacitor and a voltage dividing capacitor are connected in series to the branch line taken out for each phase of the distribution line, and the other end of the voltage dividing capacitor is connected collectively, and further a coupling filter is connected in series and grounded to form a coupler. In the distribution line control system for extracting a phase detection signal from an intermediate connection point between the high-voltage capacitor and the voltage dividing capacitor and inputting / outputting a carrier signal through the coupling filter, a primary winding is applied to both ends of the voltage dividing capacitor of the coupler. And an insulation transformer connected to one of the secondary windings on the ground side and the other as a phase detection signal output terminal. Beam.